Note 4 - Prepaid Expenses and Other Current Assets - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Prepaid employees’ benefits	$ 112	$ 112
Prepaid sales rebate	945	923
Prepaid rent		123
Rent receivable	101	86
Prepaid insurance	57	27
Prepaid fleet leasing costs	75	61
Prepaid dues and subscriptions	93	117
Other	215	214
Total prepaid expenses and other current assets	$ 1,598	$ 1,663